ICP 40VA Transformer for WAHM484A1 — 208/230V to 24V OEM 1172028 | Ships Today

Overview

This ICP OEM step-down transformer (part number 1172028) converts the 208/230V line voltage supplied to the WAHM484A1 air handler down to the 24V control voltage that powers the thermostat, relays, and low-voltage circuits. Rated at 40VA, it provides the current capacity needed for the unit's control loads. A failed transformer is one of the most common causes of a "dead" system: with no 24V output, the thermostat goes blank, contactors and relays won't pull in, and nothing runs even though line power is present. Transformers commonly fail from a shorted thermostat wire, a stuck contactor drawing excess current, or simple age.

Specifications

Compatibility

Factory replacement transformer for the ICP/Tempstar/Heil WAHM484A1 air handler and related WAHM-series units originally equipped with part 1172028. Confirm your primary voltage tap (208 vs 230) matches your supply before energizing.

Installation Guide

1. Safety First — Disconnect power at the breaker and verify zero voltage with a multimeter.
2. Access — Remove the air handler control-box service panel.
3. Document — Photograph all primary and secondary wire connections before disconnecting.
4. Remove — Disconnect the leads, unbolt the transformer from its mounting bracket, and remove it.
5. Install — Mount the new 1172028 transformer, land the correct primary tap for your line voltage, and reconnect the 24V secondary leads per your photo.
6. Test — Restore power and verify 24V across the secondary and normal system operation.

Signs You Need a Replacement

• Thermostat screen is blank and the system is completely dead.
• No 24V reading across the transformer secondary.
• Contactors or relays will not energize on a call for heat or cool.
• Visible burn marks, melted housing, or a tripped/blown control circuit.

Shipping & Returns

Ships same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.